Remove duplicated `delivery_method` definition
Remove duplicated `delivery_method` definition

`ActionMailer::Base.delivery_method` is already defined in
https://github.com/rails/rails/blob/master/actionmailer/test/parameterized_test.rb#L13

gcourtemanche/rails,gfvcastro/rails,mtsmfm/railstest,esparta/rails,felipecvo/rails,yalab/rails,xlymian/rails,jeremy/rails,baerjam/rails,betesh/rails,prathamesh-sonpatki/rails,travisofthenorth/rails,mechanicles/rails,mtsmfm/railstest,fabianoleittes/rails,Erol/rails,georgeclaghorn/rails,eileencodes/rails,illacceptanything/illacceptanything,kddeisz/rails,notapatch/rails,koic/rails,fabianoleittes/rails,repinel/rails,esparta/rails,maicher/rails,gfvcastro/rails,aditya-kapoor/rails,starknx/rails,flanger001/rails,Vasfed/rails,rafaelfranca/omg-rails,flanger001/rails,bradleypriest/rails,iainbeeston/rails,palkan/rails,EmmaB/rails-1,joonyou/rails,eileencodes/rails,yalab/rails,BlakeWilliams/rails,alecspopa/rails,ledestin/rails,riseshia/railsguides.kr,assain/rails,yasslab/railsguides.jp,arunagw/rails,mohitnatoo/rails,Stellenticket/rails,illacceptanything/illacceptanything,starknx/rails,illacceptanything/illacceptanything,utilum/rails,yawboakye/rails,printercu/rails,hanystudy/rails,Stellenticket/rails,Erol/rails,schuetzm/rails,mechanicles/rails,jeremy/rails,mohitnatoo/rails,deraru/rails,mohitnatoo/rails,rossta/rails,felipecvo/rails,kamipo/rails,MSP-Greg/rails,kmcphillips/rails,marklocklear/rails,baerjam/rails,kmayer/rails,Vasfed/rails,kmayer/rails,yhirano55/rails,pschambacher/rails,lcreid/rails,schuetzm/rails,untidy-hair/rails,esparta/rails,rafaelfranca/omg-rails,palkan/rails,tgxworld/rails,kddeisz/rails,untidy-hair/rails,yasslab/railsguides.jp,riseshia/railsguides.kr,rails/rails,rafaelfranca/omg-rails,joonyou/rails,yawboakye/rails,esparta/rails,iainbeeston/rails,Sen-Zhang/rails,printercu/rails,starknx/rails,mohitnatoo/rails,rails/rails,pvalena/rails,rossta/rails,ngpestelos/rails,gauravtiwari/rails,fabianoleittes/rails,printercu/rails,EmmaB/rails-1,mathieujobin/reduced-rails-for-travis,odedniv/rails,kirs/rails-1,odedniv/rails,xlymian/rails,kamipo/rails,Stellenticket/rails,koic/rails,Edouard-chin/rails,ngpestelos/rails,untidy-hair/rails,vipulnsward/rails,Erol/rails,illacceptanything/illacceptanything,notapatch/rails,kamipo/rails,illacceptanything/illacceptanything,assain/rails,bogdanvlviv/rails,tgxworld/rails,Stellenticket/rails,ngpestelos/rails,travisofthenorth/rails,matrinox/rails,lucasmazza/rails,travisofthenorth/rails,illacceptanything/illacceptanything,baerjam/rails,ttanimichi/rails,MSP-Greg/rails,lcreid/rails,mechanicles/rails,aditya-kapoor/rails,MSP-Greg/rails,baerjam/rails,printercu/rails,illacceptanything/illacceptanything,assain/rails,illacceptanything/illacceptanything,kirs/rails-1,kmcphillips/rails,yalab/rails,Envek/rails,gcourtemanche/rails,yhirano55/rails,xlymian/rails,pvalena/rails,gauravtiwari/rails,arunagw/rails,tjschuck/rails,rossta/rails,Sen-Zhang/rails,Envek/rails,bogdanvlviv/rails,mathieujobin/reduced-rails-for-travis,arunagw/rails,georgeclaghorn/rails,BlakeWilliams/rails,brchristian/rails,bradleypriest/rails,utilum/rails,iainbeeston/rails,yhirano55/rails,palkan/rails,iainbeeston/rails,odedniv/rails,EmmaB/rails-1,kmcphillips/rails,vipulnsward/rails,Edouard-chin/rails,yawboakye/rails,travisofthenorth/rails,Sen-Zhang/rails,tgxworld/rails,gfvcastro/rails,felipecvo/rails,yasslab/railsguides.jp,Envek/rails,yawboakye/rails,gcourtemanche/rails,utilum/rails,deraru/rails,jeremy/rails,kaspth/rails,riseshia/railsguides.kr,illacceptanything/illacceptanything,illacceptanything/illacceptanything,betesh/rails,yasslab/railsguides.jp,mechanicles/rails,deraru/rails,pvalena/rails,tjschuck/rails,tgxworld/rails,deraru/rails,marklocklear/rails,jeremy/rails,Vasfed/rails,MSP-Greg/rails,koic/rails,repinel/rails,flanger001/rails,lcreid/rails,alecspopa/rails,bradleypriest/rails,rails/rails,ledestin/rails,ttanimichi/rails,gfvcastro/rails,mtsmfm/railstest,Edouard-chin/rails,illacceptanything/illacceptanything,vipulnsward/rails,shioyama/rails,mijoharas/rails,tjschuck/rails,riseshia/railsguides.kr,flanger001/rails,yahonda/rails,hanystudy/rails,prathamesh-sonpatki/rails,rails/rails,yhirano55/rails,utilum/rails,Edouard-chin/rails,aditya-kapoor/rails,mathieujobin/reduced-rails-for-travis,assain/rails,illacceptanything/illacceptanything,Erol/rails,lcreid/rails,kirs/rails-1,BlakeWilliams/rails,mijoharas/rails,kddeisz/rails,maicher/rails,betesh/rails,bogdanvlviv/rails,vipulnsward/rails,kmcphillips/rails,yahonda/rails,Envek/rails,lucasmazza/rails,georgeclaghorn/rails,joonyou/rails,hanystudy/rails,mijoharas/rails,repinel/rails,lucasmazza/rails,shioyama/rails,yahonda/rails,betesh/rails,illacceptanything/illacceptanything,kaspth/rails,aditya-kapoor/rails,shioyama/rails,BlakeWilliams/rails,brchristian/rails,yalab/rails,maicher/rails,eileencodes/rails,arunagw/rails,ledestin/rails,ttanimichi/rails,pschambacher/rails,schuetzm/rails,pschambacher/rails,brchristian/rails,tjschuck/rails,matrinox/rails,pvalena/rails,palkan/rails,alecspopa/rails,shioyama/rails,untidy-hair/rails,fabianoleittes/rails,notapatch/rails,notapatch/rails,gauravtiwari/rails,bogdanvlviv/rails,georgeclaghorn/rails,kddeisz/rails,marklocklear/rails,yahonda/rails,prathamesh-sonpatki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